What were the balkans war?

First Balkan War (1912-1913)
Greece, Bulgaria, Serbia, and Montenegro defeat the Ottoman Empire in the First Balkan War and gain a large piece of Ottoman land in the Balkans. In the post-war conference, Austria-Hungary stepped in and created the independent nation of Albania. This was made to block Serbia from gaining access to the Adriatic, which was the country's intentions. The Austrians also became the protector of Bosnia and Herzegovina, which they later annexed to prevent a Serbian kingdom of Slavs. Serbia's other intention was to create a kingdom which unified the Slavic people in Southern Europe (which would later become mostly true with Yugoslavia after World War I). Both these events angered Serbia and thus created the feud between Serbia and Austria-Hungary.

Second Balkan War (1913)
Bulgaria, who was unsatisfied with its new territory, attacked its former allies of Greece and Serbia. Romania, who also held previous territorial-disputes with Bulgaria, joined Greece and Serbia. The Ottoman Empire, who looked at this as an opportunity to gain back some lost land, also joined in against Bulgaria. Bulgaria ended up losing and ceded most of its new territory to Greece, Serbia, and the Ottoman Empire. This also ended a previously established alliance between the Balkan nations and Russia, however, Russia's alliance with Serbia stayed in tact. The on-going feud increased between Serbia and Austria-Hungary, and Russia was too getting angry with Austria-Hungary (as it had been for a while). In 1914, Archduke Franz Ferdinand (and his wife), the heir to the Austrian throne, was assassinated by a Serbian man, Gavrilo Princip. This led to war against Serbia and Austria. Russia got involved, as it was a close ally to Serbia. France and the United Kingdom got involved as they were a part of an alliance with Russia. Germany and Italy got involved as they were part of an alliance with Austria-Hungary. Soon more and more countries got pulled in, and this is known as World War I.